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• Detailed method
• Temporary flat rate method

Detailed method (all tax years)

Steps

1. Calculate the percentage of your work space used for employment purposes

   You must first get the area of both your work space and the total finished areas of your home.

   • Size of work space (designated room or shared area)
   • divided by Total finished area of home
   • times by 100 (to convert it into a percentage)
   • equals A% Percentage of your home that you used as a work space (rounded two decimal places)

   For a description of the variables in this mathematical formula, refer to:

   • Size of your home and work space
   • Types of work spaces

   If you are working in a designated room

   Since the room is used only for work, the percentage of your home used as a work space is also the percentage of your work space used for employment purposes. You can proceed to calculate your work-space-in-the-home expenses.

   A% equals C%

   If you are working in a common (shared) area

   You need to calculate the percentage of the work space that was used for employment purposes by providing the numbers of hours worked in that space within a calendar week (7 days or 168 hours).

   • # hours (hours worked in a work week)
   • divided by 168 hours (total hours in a week)
   • times by 100 (to convert it into a percentage)
   • equals B% Percentage of the time the work space was used for work (rounded to two decimal places)

   You will now calculate the percentage of your work space used for employment purposes by multiplying these two numbers together.

   • A% Percentage of your home that you used as a work space
   • times by B% Percentage of the time the work space was used for work (rounded to two decimal places)
   • times by 100 (to convert it into a percentage)
   • equals C% Employment-use percentage of the work space (rounded to two decimal places)

   For a description of the variables in this mathematical formula, refer to:

   • Hours per week you use the space for work

2. Calculate your work-space-in-the-home employment-use amount

   You will need to first add up all of your eligible work-space-in-the-home expenses (where applicable) you paid for the period(s) you worked more than 50% of the time from home for at least four consecutive weeks for the tax year you selected.

   • Electricity, heat, water and home internet access fees
   • plus Rent (only employees who rent their home)
   • plus Maintenance costs paid that affect the entire home (for example, furnace repairs)
   • plus Home insurance (only commission employees who own their home)
   • plus Property taxes (only commission employees who own their home)
   • plusOther home expenses that include the work space
      
   • equals $D Work-space-in-the-home expenses paid for the entire home

   For a description of the variables in this mathematical formula, refer to:

   • Work-space-in-the-home expenses
   • Limitations on work-space-in-the-home expenses

   You will now calculate the portion of these expenses to claim based on what you determined to be the employment-use percentage of your work space.

   • $D Work-space-in-the-home expenses paid for the entire home
   • times by C% Employment-use percentage of the work space
      
   • equals $E Employment-use amount of work-space-in-the-home expenses for the entire home

   You must also calculate the portion of the maintenance costs paid that affect only the work space (for example, purchase of light bulbs).

   For a designated room

   • Maintenance costs paid for the work space only
   • times by 100%
   • equals $F Employment-use amount of maintenance costs for the work space only

   For a common (shared) area

   • Maintenance costs paid for the work space only
   • times by B% Percentage of the time the work space was used for work
   • equals $F Employment-use amount of maintenance costs for the work space only

   For a description of the variables in this mathematical formula, refer to:

   • Maintenance and minor repair costs

   Finally, you add the two expenses together.

   • $E Employment-use amount of work-space-in-the-home expenses for the entire home
   • plus $F Employment-use amount of maintenance costs for the work space only
   • equals $G Total employment-use amount (line 48 on the T777 form or line 12 on the T777S form)

   You will still need to complete the remainder of Form T777 to determine the final amount you can claim.

   If you are only claiming home office expenses for 2020, 2021 or 2022 using Form T777S , continue to Step 3.

3. Calculate your supplies and other expenses subtotal (line 3)

   To complete Form T777S , you will need to add together all eligible office supplies and certain phone expenses you paid.

   • Office supplies (e.g. postage, stationery, ink cartridges, other office supplies, etc.)
   • plus Other expenses (employment use of a cell phone, long distance calls for employment purposes, etc.)
   • equals $H Supplies and other expenses subtotal

   For a description of the variables in this mathematical formula, refer to:

   • Office supplies and phone expenses

4. Calculate your maximum deduction for work-space-in-the-home expenses

   To determine if you have any expenses to carry forward and to calculate the final work-space-in-the-home expenses you can claim, you must provide your employment income and the amount of certain other deductions.

   • Employment income (box 14 of your T4)
   • minus $H Supplies and other expenses subtotal
   • minus Annual union, professional, or like dues (line 21200 from your return)
   • minus Registered Pension Plan (RPP) deduction (line 20700 of your return)
   • equals $I Maximum deduction for work-space-in-the-home expenses

5. Calculate the amount to carry forward

   To calculate any amount to carry forward, you must subtract your maximum deduction for work-space-in-the-home expenses from the total employment-use amount of the expenses you paid.

   • $G Total employment-use amount (line 12 on the T777S form)
   • minus $I Maximum deduction for work-space-in-the-home expenses
      
   • equals $J Total amount to carry forward (if negative, enter "0")

6. Calculate the total home office expenses you can claim

   To calculate the total home office expenses you can claim, you must add up a few of previous amounts you have calculated.

   • $H Supplies and other expenses subtotal
   • plus

     The work-space-in-the-home expenses entered on line 9945 of Form T777S, which is the lesser of either:

     • $G Total employment-use amount

     • $I Maximum deduction for work-space-in-the-home expenses
      
   • equals $K Total home office expenses you can claim, which you enter on line 9368 of Form T777S and on line 22900 of your return

Temporary flat rate method for 2020, 2021 and 2022

• # of days you worked from home during the COVID-19 pandemic in 2020 (maximum 200), in 2021 (maximum 250), or in 2022 (maximum 250)
• times by $2 (temporary flat rate amount)
• equals Amount of your claim (to a maximum of $400 in 2020 or up to $500 in 2021 and 2022)

For a description of the variables in this mathematical formula, refer to:

• Eligibility criteria – Temporary flat rate method
• What counts as a work day at home